In early returns Tuesday night, voters are rejecting I-522, which would require the labeling of certain foods and seeds containing genetically modified organisms, or GMOs. No votes were at 55 percent and yes votes at 45 percent.

If voters approve I-522, Washington would be the first state to put in place labeling requirements for genetically modified foods.

If the initiative passed, labels on packaged processed foods would read "partially produced with genetic engineering" or "may be partially produced with genetic engineering."

Genetically engineered raw agricultural commodities would be labeled conspicuously with the words "genetically engineered," the Secretary of State's office reports.

"This is far from over and we have several days of vote counting ahead," said Delana Jones, campaign manager for the Yes on 522 campaign, noting that about 300,000 projected votes in King County, where the measure showed strong support, have not yet been counted. "I'm cautiously optimistic."

It's become the most contentious and expensive issue on the November ballot. Big money has poured in on both sides.

"No on 522" raised over $21 million to defeat the measure, much of that coming from food companies like Coca-Cola, General Mills and Nestle USA, as well as biochemical companies like Monsanto.

Dana Bieber, with the No on 522 campaign, says the measure was defeated in California and should be defeated in Washington as well because the labels would be "inaccurate, incomplete and inconsistent."

"Information is only useful if it's accurate, and that's where Initiative 522 fails consumers," says Bieber.

"We label if a juice is from concentrate or not. We label whether or not an ingredient is artificial or not. Even though the artificial vanilla is molecularly identical to the natural vanilla, we have a right to know it's artificial," argues Bronner.

"We are in America. We have a right to know what we want to know about our food," adds Bronner.

Only about 6 percent of the roughly $30 million raised by both sides has come from within Washington state, according to campaign finance reports.

While it would affect many foods, a number of others would be exempt, including alcoholic beverages, certified organic foods served in restaurants or in food service establishments, and foods from animals that have not been genetically engineered, regardless of whether they've been fed any genetically engineered food.